The microelectronic industry relies on a variety of different processes to manufacture microelectronic devices. Many processes involve a sequence of treatments in which different kinds of treatment fluids are caused to contact the workpiece in accordance with desired recipes. These fluids may be liquids, gases, or combinations thereof. In some treatments, solids may be suspended or dissolved in a liquid or entrained in a gas.
Innovative tools for processing microelectronic workpieces are described in Assignee's co-pending U.S. patent application Ser. No. 11/376,987, now issued as U.S. Pat. No. 7,681,581 (hereinafter referred to as the Co-Pending Application No. 1); Assignee's co-pending U.S. patent application Ser. NO. 11/376,996, titled BARRIER STRUCTURE AND NOZZLE DEVICE FOR USE IN TOOLS USED TO PROCESS MICROELECTRONIC WORKPIECES WITH ONE OR MORE TREATMENT FLUIDS, in the names of Collins et al., filed Mar. 15, 2006, now published as U.S. 2007/0245954-A1 (hereinafter referred to as the Co-Pending Application No. 2) and being a counterpart to PCT published application WO 2006/107550; Assignee's Co-Pending U.S. patent application Ser. No. 11/820,709 titled BARRIER STRUCTURE AND NOZZLE DEVICE FOR USE IN TOOLS USED TO PROCESS MICROELECTRONIC WORKPIECES WITH ONE OR MORE TREATMENT FLUIDS, in the names of Collins et al., filed Jun. 20, 2007, now published as U.S. 2008/0008834-A1 (hereinafter referred to as Co-Pending Application No. 3); and Assignee's Co-Pending application Ser. No. 12/220,887, now issued as U.S. Pat. No. 7,913,606 (hereinafter referred to as the Co-pending Application No. 4). The entireties of these co-pending U.S. Patent Applications and these publications are incorporated herein by reference for all purposes.
The processing sections such as “processing section 11” of the co-pending U.S. Patent Application No. 1 advantageously includes nested duct features that allow one or more duct pathways to be selectively opened and closed. For example, when the structures are moved apart relatively, a duct pathway opens and is enlarged between the structures. When the structures are moved together relatively, the duct between the structures is choked and is reduced in size. In preferred embodiments, multiple ducts can exist in the same volume of space depending upon how the moveable duct structures are positioned. Thus, multiple ducts can occupy a volume minimally larger than the volume occupied by only a single duct. Because of the nested character of the duct structures, the duct system is extremely compact. The ducts are used to capture various treatment fluids, including liquid and/or gases, for recycling, discarding, or other handling. Different treatment fluids can be recovered in different, independent ducts to minimize cross-contamination and/or to use unique capture protocols for different fluids.
These co-pending U.S. Patent Applications also describe an innovative spray nozzle/barrier structure. This structure includes capabilities for dispensing treatment materials in multiple ways such as by a spray, a center dispense, and a showerhead. The barrier structure overlies the underlying workpiece. The lower surface of the barrier structure is shaped in preferred embodiments so that it defines a tapering flow channel over the workpiece. This approach offers many benefits. The tapering flow channel helps to promote radial flow outward from the center of the workpiece while minimizing recirculation zones. The taper also helps to smoothly converge and increase the velocity of flowing fluids approaching the outer edge of the workpiece. This helps to reduce liquid splash effects. The angle of the lower surface also helps liquid on the lower surface to drain toward the outer periphery where the liquid can be collected and removed such as by aspiration as taught in Assignee's co-pending Application No. 3. The tapering configuration also helps to reduce recirculation of particles back onto the workpiece. The configuration also helps facilitate chemical reclaim efficiency by better containment of fluids.
Notwithstanding all these benefits, further improvements are still desired. In particular, it would be desirable to use the tools described in Assignee's Co-Pending Applications Nos. 1 to 4 to carry out treatments in an environmentally isolated processing chamber. This might be desired anytime a controlled atmosphere is desired. One controlled atmosphere under investigation is an atmosphere with low or even substantially no oxygen content. The reduction in or substantial absence of oxygen helps prevent the corrosion of materials on an in-process microelectronic workpiece that might be vulnerable to oxidation. The current embodiments of these tools use a shutter around the showerhead and air intake components to help seal off the intake of ambient air into the process chamber. However, more ambient air than might be desired can still enter the process chamber from around the conventional showerhead and air intake design even when the shutter is closed. Additionally, these tools include an annular gap between the barrier plate and the surrounding baffle components. Ambient air can also enter the process chamber through this gap.
According to one option, such gaps can be eliminated by designing the tools in such a way that the components come into direct physical contact to close the gap in order to provide the desired seal. However, this kind of contact among the moving component(s) may be undesirable for at least two reasons. Firstly, contaminating particles may tend to be generated by the kind of force that would be needed to generate a good seal around the entirety of the gap. Second, it is often desirable to use stepper motors to control the movement of such components so that a controller can track the motor steps and hence the position of these components at any time. However, the kind of force needed to establish a good seal around the entire gap could tend to cause a controller to lose count of the motor steps. The ability to know and control movements of the components would be compromised when the stepper motor count is lost. These same concerns are at play when the shutter referred to above is deployed using stepper motor(s)
Clearly, being able to carry out treatments in isolation from the ambient is highly desirable. Yet, having a process chamber that can only operate in substantially full isolation from the environment is not always desirable, either. Many manufacturing strategies involve a series of treatments that involve both closed (i.e., isolated from sources of ambient air) and open (i.e., coupled to sources of ambient air) modes of operation. Of course, a manufacturing facility could procure separate, dedicated tools that operate in either a closed or open mode, respectively. But, such tools are quite expensive and represent a significant investment. Multiple tools occupy correspondingly larger portions of valuable facility space, too.
Accordingly, it is desirable to provide a tool that can effectively operate in either closed or open modes of operation with the capability to easily transition between open and closed modes on demand.